package com.sky.service.impl;

import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.entity.ShoppingCart;
import com.sky.exception.ShoppingCartBusinessException;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.mapper.ShoppingCartMapper;
import com.sky.service.ShoppingCartService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.List;

@Service
public class ShoppingCartServiceImpl  implements ShoppingCartService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;

    @Autowired
    private DishMapper dishMapper;

    @Autowired
    private SetmealMapper setmealMapper;

    /**
     * 添加购物车
     *
     * @param shoppingCartDTO
     */
    public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        //只能查询自己的购物车数据
        Long currentId = BaseContext.getCurrentId();
        if (currentId == null) {
            throw new ShoppingCartBusinessException("用户未登录");
        }
        shoppingCart.setUserId(currentId);

        //判断当前商品是否在购物车中
        List<ShoppingCart> shoppingCartList = shoppingCartMapper.list(shoppingCart);

        if (shoppingCartList != null && shoppingCartList.size() == 1) {
            //如果已经存在，就更新数量，数量加1
            shoppingCart = shoppingCartList.get(0);
            shoppingCart.setNumber(shoppingCart.getNumber() + 1);
            shoppingCartMapper.updateNumberById(shoppingCart);
        } else {
            //如果不存在，插入数据，数量就是1

            //判断当前添加到购物车的是菜品还是套餐
            Long dishId = shoppingCartDTO.getDishId();
            if (dishId != null) {
                //添加到购物车的是菜品
                Dish dish = dishMapper.getById(dishId);
                if (dish == null) {
                    throw new ShoppingCartBusinessException("菜品不存在");
                }
                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());
            } else {
                //添加到购物车的是套餐
                Long setmealId = shoppingCartDTO.getSetmealId();
                if (setmealId == null) {
                    throw new ShoppingCartBusinessException("请选择菜品或套餐");
                }
                Setmeal setmeal = setmealMapper.getById(setmealId);
                if (setmeal == null) {
                    throw new ShoppingCartBusinessException("套餐不存在");
                }
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());
            shoppingCartMapper.insert(shoppingCart);
        }
    }

    /**
     * 查看购物车
     * @return
     */
    public List<ShoppingCart> showShoppingCart() {
        return shoppingCartMapper.list(ShoppingCart.
                builder().
                userId(BaseContext.getCurrentId()).
                build());
    }

    @Override
    public Object sub(ShoppingCartDTO shoppingCartDTO) {
        //删除一个购物车商品
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        shoppingCart.setUserId(BaseContext.getCurrentId());
        
        // 先查询是否存在该商品
        List<ShoppingCart> shoppingCartList = shoppingCartMapper.list(shoppingCart);
        if (shoppingCartList != null && !shoppingCartList.isEmpty()) {
            ShoppingCart existingCart = shoppingCartList.get(0);
            if (existingCart.getNumber() > 1) {
                // 如果数量大于1，减少数量
                existingCart.setNumber(existingCart.getNumber() - 1);
                shoppingCartMapper.updateNumberById(existingCart);
            } else {
                // 如果数量为1，直接删除该记录
                shoppingCartMapper.deleteOne(shoppingCart);
            }
        }
        
        return null;
    }

    @Override
    public Object clean() {
        shoppingCartMapper.clean(BaseContext.getCurrentId());
        return null;
    }
}